AbstractFive ras genes (rasB, rasC, rasD, rasG and rasS) and one rap gene (rap1) have been isolated and characterized in the cellular slime mold Dictyostelium discoideum (Daniel etal. 1993,1994; Reymond etal. 1984; Robbins eta/. 1989,1990). These ras subfamily genes encode 21-22 kDa GTP-binding proteins that have 52-68% amino acid identity with the human H-Ras protein (Table 1). These genes all appear to be present in a single copy since each of their cognate cDNAs hybridizes to a single, unique genomic fragment under high stringency conditions.
